1. Field of the Invention
The present invention relates to a stop device which stops a workpiece being conveyed by abutting against it.
2. Description of the Related Art
A stop device is known which stops a workpiece conveyed on a conveyance device such as a roller conveyor at a predetermined position. The stop device stops a workpiece or releases the stopped workpiece by advancing or retracting an abutment portion such as a roller abutting against the workpiece on or from a conveyance device. The stop device therefore requires a mechanism or actuator which reciprocates the abutment portion. As an actuator for the stop device, an air cylinder capable of generating driving forces in two directions is often used because the abutment portion needs to be reciprocated (patent literatures 1 to 3).